Retaining ring assembly tools



Jan. 15, 1963 H. ERDMANN 3,073,014

RETAINING RING ASSEMBLY TOOLS Filed April 1, 1960 3 Sheets-Sheet lINVENTOR HANS E R0 ANN ATTORN Jan. 15, 1963 H. ERDMANN 4 RETAINING RINGASSEMBLY TOOLS Filed April 1, 1960 s Sheets-Sheet INVENTOR HANS ERMANNJan. 15, 1963 H. ERDMANN 3,073,014

RETAINING RING ASSEMBLY TOOLS Filed April 1, 1960 5 Sheets-Sheet 3 Z fiFIG. I!

FIG. /3

INVENTOR gflA/VS ERD ANN r ATTORNE United States Patent 3,073,014RETAINING RING ASSEMBLY TOOLS Hans Erdmann, Maplewood, N.J., assignor toWaldes Kohinoor, Inc., Long Island City, N.Y., a corporation of New YorkFiled Apr. 1, 1960, Ser. No. 19,207 16 Claims. (Cl. 29-229) Thisinvention relates to improvements in retainingring assembly tools and ismore particularly directed to an improved hand tool of the typegenerally disclosed and claimed in my prior applications Serial No.817,668, filed June 2, 1959, now Pat. No. 3,015,882, and Serial No.835,222, filed August 21, 1959, now Pat. No..

3,012,313, for assembling so-called split spring retaining rings ongrooved shafts, pins and like cylindrical workpieces.

While effective for their intended purpose, the tools of my priorapplications aforesaid are'relatively complicated both as to theirstructure and respective modes of operation. In explanation, the .priortools operate on the principle of spreading a split ring to be assembledfrom its free or unstressed diameter to one slightly exceeding thediameter of the shaft in whose groove it is to be assembled by pushingthe ring axially along a tapered spreading mandrel by force exertedagainst a face thereof, such axial movement of course being in additionto the further movement required to move the spread ring axially alongthe shaft to the plane of its groove, with the result that the priortools are required to have not only an accurately configured anddimensioned spreading mandrel or head but also their design must be suchas to provide a substantial length of working stroke of the spreadinghead and/or the related push head.

A tool according to my earlier filed application Serial No. 817,668, nowPat. No. 3,015,882, has also been found to be somewhat slow and awkwardin its operation, since to be capable of picking up a ring to beassembled from the conventional dispenser therefor and thereupon ofassembling the ring on its usuallyupright shaft from above, it Wasnecessary to first invert and then upright the tool, all preliminary tothe actual ring assembly operation. Although the assembly tool of myaforesaid later filed application Serial No. 835,222, now Pat. No.3,012,313, overcame this requirement of preliminary tool inversion anduprighting, the later devised tool was still open to the criticismsometimes leveled at the basic tool which it sought to improve that therings to be assembled could be picked up by said tool only if and whenphysically positioned between the so-called push and spreading head ofsaid tool, thus necessitating room both above and below the dispensertable or shelf to accommodate said heads in their spaced ring pick-upposition.

Stated broadly, a major object of the present invention is the provisionof a hand tool for assembling split spring retaining rings on shaftsandsirnilar cylindrical workpieces, which is simpler and less expensiveto manufacture than the tools serving similar function according to myprior applications Serial Nos. 817,668 and 835.222, now Patent Nos.3,015,882 and 3,012,313 respectively, and which further has theadvantage that it may he more easily operated as well as being capableof assembling rings in grooves which are spaced a greater distance fromthe ends of said workpieces than the tools of my applications aforesaid.

Another important object of this invention is the provision of aneifective hand tool for assembling split spring retaining rings onshafts and similar cylindrical workpieces which does away not only withthe tapered 2 spreading head but also with the requirement ofsubstantially shifting the ring in axial direction as a condition to itsbeing spread, as characterizes the tools of my aforesaid priorapplications, thus simplifying both the operation and the mechanicaldesign of the tool, the latter in part by substantially lessening theworking stroke of tool parts.

Another practical object of the invention is the provision of animproved hand tool as aforesaid which is capable of simply andeffectively assembling split spring retaining rings in the grooves ofupright shafts and similar grooved cylindrical workpieces, without anyrequirement on the part of the operator to perform the cumbersome stepsof first inverting the tool to grasp each ring to be assembled andthereupon of uprighting it to apply the ring to the upper end of saidworkpieces, as characterizes a tool according to my prior applicationSerial No. 817,668 aforesaid.

Yet another object of the invention is the provision of an improved handtool for assembling split pen retaining rings in the grooves of shaftsand similar grooved cylindrical workpieces which operates on theprinciple of the rings to be assembled being spread from within byeffective diametrical separating movement of two relatively separablemandrel parts whose separating and coming-together movements are subjectto positive control by the tool operator.

A more detailed object of the invention is the provision of an effectivehand tool for assembling split spring retaining rings as aforesaid bythe spreadingactio'n of complemental, spreadable mandrel parts mountedfor ,swinging movement in unison along arcuate paths which mutuallyintersect and whose ring spreading and nonspreading positions thusdepend on simple swinging movement imparted to said mandrel parts alongsuch paths.

Yet another object of the invention is the provision of an improved toolas last aforesaid, wherein said mandrel parts and their mounting meansare so constructed and arranged that when swung relatively downwardly inunison throughout a predetermined arc the mandrel parts are closelyrelated to a degree that they may readily enter the ring opening andsecure to said ring and that when they are swung upwardly or in thereturn direction they separate from one another and in so doing exertradial outward spreading force on the ring as effects controlledspreading thereof.

A still further object of the invention is the provision of an improvedhand tool for spreading split retaining rings employing spreadable partsoperative to spread the ring from within by their relative radialoutward movement, and wherein one of said parts is constructed andarranged so as to be capable of knifing into the gap between the splitor open ends of the ring with a wedging action when partaking of itsrelative radial outward movement.

Another object of the invention is the provision of an improvedpliers-type hand tool of the last above character wherein said one partis movable into the ring gap in successive stages, thus providing amulti-stage ring spreading action.

Yet another object of the invention is the provision of an improved handtool as last aforesaid, wherein the first stage of ring spreading iseffectively utilized in enabling the tool to pick up the ring with whichit is cooperated and the later stage or stages of such spreading effectsspreading of the ring the amount permitting'it to be readily shiftedover the end of its shaft.

Still another object of the invention is the provision of a hand toolfor assembling split spring retaining rings on shafts and likecylindrical workpieces incorporating an effectively radially-spreadablemandrel capable in its non-spread relation of being readily insertableinto the opening of a ring to be assembled and in its spread relation ofspreading the ring from within, combined with a push means effective toexert push on the face of such a spread ring as provides for its axialmovement over and thence along the end of the shaft on which it is beingassembled to the plane of its groove.

A further more specific object of the invention is the provision of apliers-type hand tool as last aforesaid, wherein the mandrel is biasedby the design of the tool towards. its spread relation thereby torelieve the operator to some degree of applying spreading force tothering.

Still another object of the invention is the provision of a hand toolfor assembling split spring retaining rings in the grooves of shafts andsimilar cylindrical workpieces whose construction and arrangement issuch that it incorporates tool-to-ring guiding means, ring pick-up meansand ring spreading means combined in a simple mandreltype tool head.

A final object of the present invention is the provision of a hand toolfor assembling split spring retaining rings on grooved shafts and thelike which is economical'to manufacture, simple and eificient to use,and yet performs its ring pick-up, spreading and assembling functions inmore highly satisfactory manner than heretofore achieved.

The above and other objects and advantages of the improved hand tool forassembling split spring retaining rings according to the presentinvention will appear from the following detailed description thereof,taken with the following illustrative drawings showing preferred but notnecessarily the only forms which such a tool may take, wherein:

FIG. 1 is a side elevational view, partly in section, of the pliers-typetool of this invention in the normal or rest position in which thecomplemental tip members constituting the spreading mandrel or head arein a fully spread condition;

FIG. 2 is a top plan view thereof, also partly in section;

FIG. 3 is a front end elevational view thereof;

FIG. 4 is a side elevational view of the herein tool associated with aconventional ring dispenser which illustrates the manner of operatingthe aforesaid tool in picking up a ring to be assembled seated in thenest or pocket of the dispenser;

- FIG. 5 is a view generally similar to FIG. 4 which illustrates theaction of the tool and relation assumed by the tool parts in grippingthe ring following its being picked up as in FIG. 4;

FIG. 6 illustrates the tool preliminarily engaged with the workpiecepreparatory to the ring applying operation;

FIG. 7 shows the tool as having just completed the ring applying orassembling operation;

FIG. 8 is a motion diagram which graphically depicts the principle ofthe separating and receding motion of the complemental tip membersconstituting the spreading mandrel;

FIG. 9 is an enlarged side elevational framentary view of the ringspreading mandrel, with the complemental parts thereof shown in theirfully closed position corresponding to that of FIG. 4; with FIG. 10being a front end view and FIG. 11 a vertical section taken on line 11of FIG. 9;

FIG. 12 is a bottom view of the closed mandrel as shown in FIG. 9, whichillustrates its ready insertability in the opening of a split retainingring being picked up thereby, which ring is shown in broken lines;

FIGS. 13 and 14 are views corresponding to the afore-' said FIGS. 9 and12, which illustrate the complemental mandrel parts partially spread asin FIG. 5; and

FIGS. 15 and 16 are further views corresponding to FIGS. 9 and 12, whichillustrate the complemental mandrel parts in the fully spread relation.

Referring to the drawings in detail, a tool according to the presentinvention basically comprises a grip handle 10 preferably consisting ofan elongated, rectangular holsaid frame by vertically spaced pins 15, 16and whose forward working ends extend well beyond the forward end of thehandle and terminate in right-angularly disposed and complementaldepending tip members generally designated 17, 18, later described indetail; and ring-push-means comprising forwardly reaching springy arms19, 20 integral with the frame side walls 11a, 11b and terminating independing semi-cylindrical extensions 19a, 20a together forming agenerally tubular push head, the diameter of which is slightly largerthan the inner diameter of the ring to be assembled and approximatelyequal to the diameter of the shaft in whose groove the ring is to beseated, thus being operative to push a ring with which it has faceengagement axially along said.

shaft.

As best seen in FIGS. 1 and 5, the upper and lower arms 13, 14 whichhave bar section and preferably ex tend in close edge-to-edge relationsoas to be mutually operable one by the other are normally urged to aposition in which they are square with the handle 16 (as in FIG. 1),i.e. their longitudinal center lines extend parallel with that of thehorizontal center line of the handle and hence at right angles to thevertical line of their pivots 15, 16, by a spring 22 shown to bereactive between a fixed frame-mounted pin 23 and the end of the lowerlever arm 14 which extends to the rear of its pivoting pin 16. However,the lever arms are swingable in unison against the force of said springto a position in which their forward working ends incline downwardlyfrom the handle (as in FIG. 5), as by means of a finger piece 24 shownto project upwardly from the forward end of the upper lever arm 13.During the course of their movement from and to their FIG. 1 position,the lever arms move in a common plane which is intermediate that of thefixed arms 19, 20 carrying the aforesaid push head.

According to the invention, the aforementioned ring spreading mandrelconstituted by the complemental tip members 17, 18 is speciallyconstructed so as to be capable of performing the manifold functions ofguiding the tool to a ring to be assembled seated in the ring nest orpocket of a ring dispenser, for example, thereupon of gripping the ringalong its inner and gap edges so that it can be lifted from thedispenser and transported by the tool to the shaft in whose groove it isto be assembled, and finally of spreading the ring to the diameter ofsaid shaft as permits its ready application to the shaft by the pushhead. More in detail, the tip member 17 provided on the upper lever arm13, which has predetermined greater length than the lower companion arm14, may be formed initially cylindrical throughout its length, either asan integral part of the forward end of said arm 13 or as a separate partafiixed to said end by welding or riveting, and has diameter slightlyless than that of the inner circle of the rings being assembled.However, its lower end portion which is disposed forwardly of theforward free end of the related lever arm is cut away or relieved so asto have semi-cylindrical formation as at 17A and is disposed so as topresent its transversely extending plane face a to the end of saidrelated lever arm.

7 As is best shown in FIGS. 9 and 11, for example, the,

cludes a combination spreader and guide blade 18B which dependsdownwardly from its front lower corner, said blade having generally thesame thickness as that of the tip member proper except as hereinafternoted.

As is seen in FIGS. 9, l3 and 15, the upper section or portion of saidblade 1813 (which constitutes the spreader blade proper) is disposed atthesarne level as the lower end of the tip member 17, and its rearwardworking edge 18E which preferably has curvature corresponding to that oftip end 17A of the complemental tip member 17 is further provided in itsside corners with a pair of upwardly converging notches which deepen asthey extend upward-1y, thus to define double-wedge surfaces 18F whichincline oppositely toward one another and have progressively greaterlateral extent towards the upper line of said blade. In contrast, therearward edge of the lower section or half of said'blade 18B(hereinafter designated 1 86) which has generaly similar curvature issloped forwandly or towards the tip member 17 by a small angle.

In a properly designed tool as aforesaid, the mandrel constituted bysaid complementa-l tip members 17, 18 will have as its greatesteffective diameter, i.e. a front-torear diameter extending to andterminating re-arwardly at said rearward edge 18E, one such diameterwhich provides the desired maximum spreading of the ring to bessembledand will have as its minimum diameter one such diameter which isslightly less than that of the inner circle of the rings to beassembled. Thus, as the mandrel-forming tip members 17 and 18 arebrought together so that their adjacent faces a and b abut orsubstantially abut one another, the lower end of the mandrel can bereadily inserted into the opening of a ring positioned to receive same(as in a dispenser, FIG. 4), being guided in such movement by the guideportion 18G of the spreader blade 188 whose formation is such as toprovide effective tool-to-ring guidance. Conversely, as the tip membersare spread apart their maximum amount (as in FIGS. 1, 7 and 15, 16), thering being operated on by said tip members will be spread to a diameterslightly larger than that of the grooved shaft on which it is to beassembled.

The requisite translatory movement providing for closing and separatingmotion of the mandrel-forming tip members 17 and 18 is simply achievedin the herein tool bythe aforesaid mounting and disposition of the leverarms 13, 14 and tip members as well. That is to say, consequent to thevertical spacing of the pivots 15, 16, the greater length of the upperlever arm 13 as compared to that ofthe lower lever arm 14, and thedepending rightang'ular disposition of the tip members with respect tosaid arms, the normally spaced, adjacent faces a, b of the tip memberswill approach and finally abut one another as said lever arms are swungdownwardly relative to the handle it from their FIG. 1 to their FIG. 4positions, for example, consequent to said faces moving in arcuate,mutually intersecting paths as is graphically illustrated in FIG. 8. Itfollows, of course, that two diametrically opposed points on thefront-to-rear diameter of said mandr'el, i.e. the diameter of the circleof the tip member 17 continuing through the working edge 18E of thecompemental tip members 18, will .move together, thus in effectdecreasing said diameter an amount permitting the insertion of the lowerfree end of the mandrel into the opening of a ring to be assembled.Conversely, as said lever arms 13, 14 swing or are swung back to theirinitial or FIG. 1 position with respect to the handle 10, the faces a, brecede from one another, as effects spreading of the ring positionedthereon to substantially the diameter of the shaft on which it is to beapplied.

While the operation of the above described and illus-. t-rated tool willbe obvious to those skilled in the art, it will be briefly explained asfol-lows: Assuming the tool is in its normal position shown in FIG. 1,in which the lever arms 13, 14 are horizontal with the handle and themandrelaformin-g tip members 17, 18 are spread the maximum permissibleamount, the operator, upon picking up the tool and bringing its forwardworking orm-andr'el' end directly over a ring R disposed in theassembly-ready position in thenest or pocket ,P of a dispenser D asgenerally illustrated in FIG. 4, depresses the finger piece 24 therebyswinging said lever arms 13, '14 downwardly with respect to the handleuntil the tip-member faces a and b abut or substantially abut oneanother. In such extreme arm position, the mandrel is disposed fullybelow the part tubular push head 19a, 20a and, equally important, it isin effect closed to its smallest possible diameter, which as aboveexplained is such as to enable ready insertion of its lower end into theopening of ring R, which inserting movement is facilitated by thetapered guide extension 18G of the spreader blade 18B.

The operator then proceeds to insert the free or lower end of the closedmandrel to the maximum possible depth (see FIGS. 9 and 13) into the ringopening, of course being careful to orient the tool with respect to thering so that working edge 18E is aligned with the narrowwidth gapcharacterizing split or nearly closed spring retaining rings, such beingbest illustrated in FIG. 12. Thereupon the operator releases the fingerpiece 24, such resulting in the lever arms 13, 14 tending to and in factpartially returning to their initial or FIG. 1 position underbias ofspring 22 as effects partial spreading of the tip members 17, 18.Consequent thereto, the spreader blade 18B knifes into the gap a limiteddistance but one which is nonetheless sufiicient to insure the mandrelfirmly grip-' ping or grasping the ring R at diametrically spaced pointsalong its inner and gap edges, and further to effect a first-stagespreading of said ring. The degree of such ring gripping and spreadingwill of course depend on the.

force exertable by the spring 24, but preferably this is not sufiicientas of itself to effect maximum ring spreading. FIGS. 5, 13 and 14generally illustrate the relationship assumed by the tool partsfollowing release of the finger piece 24 as aforesaid.

With the ring .now firmly held by the tool, the'latter may be used tocarry it to the grooved shaft or other cylindrical workpiece on which itis to be assembled, such as the shaft S held in upright position in afixture F (FIGS. 6 and 7). To finally assemble the ring, the tool isengaged with the shaft as shown in FIG. 6 and at this point it is notedthat the forward vertical edge of the guide portion 18G of the spreadingblade 18B is cut back so as not to interfere with the mandrel aligningwith said shaft and at the same time to aid in tool-to-shaft engagement.Upon proper tool-on-shaft engagement having been obtained,

the operator then exerts firm downward pressure on the handle which justpreviously has assumed an upwardlyforwardly inclined attitude (FIG. 6).As the result thereof, the handle is brought back into horizontalparallelism with the lever arms 13, 14, the mandrel is spread themaximum permissible amount as effects secondor final-stage spreading ofthe ring (see FIGS. 15 and 16) during the course of which the ring firsttends to hug the spreader blade 1813 because of the upward inclinationof the doublewedge faces 18F, and, finally, the push head 19a, 20a,which upon arms 13, 14 and handle 12-being brought into parallelism asaforesaid is coaxial with the now fully spread mandrel, progressivelyengages on the upper'face of the ring, -skins it from the mandrel, andin its final movement pushes the ring over and along the shaft end .tothe plane of the groove g. Upon arriving at the groove, the ring snapsinto the groove and the tool is now withdrawn from the shaft, fullyconditioned for the next ring assembly operation.

In connection with the aforementioned ring dispenser D, suchillustratively comprises a base B mounting a pivotally hung stack rod SRbiased by a spring SP to a position in which it normally disposes thesupply of rings R-l mounted thereon above and in substantially verticalalignment with said ring nest or pocket P. However, due to its aforesaidmounting, the stack rod is free to swing rearwardly when its stack ofrings is engaged by the tool push head 19a, 20a moving against same (asin FIG. 4), thus to make the tool mandrel and ring R seated in thepocket P mutually accessible to one another. It is observed that thetool-to-ring guide blade 18G also serves to align the tool with the ringpocket by its ability to engage the wall thereof and thereby find itsproper position above the pocket.

Without further analysis, it will be appreciated that the herein handtool as described and illustrated achieves the stated objectivestherefor, i.e. a tool ofsimple, inexpensive construction which is easyto operate, has a short working stroke, requires no inversion, etc.However, as many changes could be made in carrying out the aboveconstructions without departing from the scope of the invention, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

I claim:

1. A hand tool for gripping split spring retaining rings from within theopening thereof and thereupon assembling said rings on grooved shaftsand like cylindrical workpieces comprising, in combination, an elongatedhandle member, complemental and diametrically translatable memberstogether forming a ring gripping and spreading mandrel, parallel armmeans pivotally connected to said handle member adjacent their rearwardends and extending forwardly from said handle and mounting said tipmembers at their relatively forward ends in generally right-angular andmandrel-forming relationship with re spect to. said handle member, thepivotal connections of said arm means to handle member permittinglimited relative rotational movement of the handle member with respectto said arm means, the length of said arm means and the locations oftheir pivotal connections to the handle member being such thatrotational movement of the arm means in unison with respect to thehandle member in one direction effects swinging movement of the tipmembers in mutually intersecting arcs as effects translatory movement ofsaid mandrel-forming tip members towards one another by an amount suchthat the mandrel has effective diameter slightly less than that of theopening of a ring to be assembled and that subsequent rotationalmovement of the handle member in the opposite direction effects swingingmovement of the tip members in mutually diverging paths as effectstranslatory movement of said mandrel-forming tip members away from oneanother by an amount-such that the mandrel has effective diametercorresponding substantially to that of the shaft on which said ring isto be assembled, and mandrel-telescoping means fixedly mounted on aforward extension of said handle member in general axial alignment withsaid mandrel and being adapted to telescope over said mandrel responsiveto rotational movement of said handle with respect to the arm means asaforesaid, thereby to push a ring which has been gripped and spread bysaid mandrel axially therefrom and thence over an end of the shaft tothe plane of the ring-seating groove thereof.

2. A hand tool according to claim 1, wherein one of said tip members hasdouble-wedge section defining a narrowing edge which is adapted in themovement of the tip members to their relative positions of maximumseparation to knife into the gap of a ring which said mandrel hasgrippingly engaged.

3.'A hand tool according to claim 1, wherein one tip member hassubstantially semi-cylindrical section and diameter slightly less thanthat of said ring opening.

4. A hand tool according to claim 1, wherein one tip member hassubstantially semi-circular section and diameter slightly less than thatof said ring opening and the complemental tip member has double-wedgesection defining a narrowing edge which is adapted during the course ofmovement of the tip members to their relative positions of maximumseparation to knife into the gap of a ring which said mandrel hasgrippingly engaged.

5. A hand tool according to claim 1, wherein said handle mounts meansfor biasing said complemental tip members toward their relativepositions of maximum separation.

6. A hand tool according to claim 5, wherein said last means includes aspring capable of providing a biasing force sufiicient to effect afirst-stage movement of said tip members from their relative positionsof minimum spacing toward their relative positions of maximum spacing asaforesaid. A

7. A hand tool according to claim 1, wherein one of said tip membersincorporates tool-to-ring guide means depending relatively downwardlytherefrom and being shaped to facilitate initial engagement of the,mandrel with the ring to be assembled.

8. A hand tool according to claim 1, wherein said arm means mounts afinger piece projecting therefrom forwardly of the handle member forimparting rotational movement of said arm means in said one directionwith respect to the handle member.

9. A hand tool for gripping split retaining rings from within theopening thereof and thereupon assembling said rings on grooved shaftsand like cylindrical workpieces comprising, in combination, a handlemember, a pair of parallel lever arms disposed in overlying relationwith their working ends extending forwardly from the handle and beingpivotally connected at their corresponding rearward ends to the rearwardend of the handle member at relatively vertically spaced points thereoffor limited rotational movement with respect to said handle member, theworking ends of the said lever arms carrying depending complemental tipmembers disposed at substantially right angles to said arms and whichtogether form a two-part closable and spreadable ring gripping andspreading mandrel having, when the tip members are in their closedposition, an effective diameter which is slightly less than that of thering opening and, when the tip members are spread a predeterminedpermissible amount, an effective diameter which is slightly greater thanthat of said shaft, the length of said arms and the points of theirpivotal connection to the handle member being so located that rotationalmovement of the arms in unison and in one direction relatively to thehandle member effects translatory movement of said tip members to theirclosed position in which the mandrel has minimum efiective diameterwhich is slightly less than that of the opening of the ring to beassembled and that subsequent rotational movement of the handle memberin the opposite direction effects translatory motion of said tip membersto their open position wherein the mandrel has maximum effectivediameter corresponding to that of the shaft on which said ring is to beassembled, and mandrel-telescoping means affixed to a forward extensionof said handle member and in generally axial alignment therewith, saidtelescoping means being adapted to telescope over the mandrel responsiveto said opposite rotational movement of the handle member with respectto said arms and being operative during such movement to push a ringwhich has been gripped and spread by said mandrel axially therefrom andthence over the end of the shaft to the plane of the ring-seating groovethereof.

10. A hand tool according to claim 9, wherein one of said tip membershas semi-cylindrical formation and the other tip member is formed as adouble-face wedge terminating in a narrowing edge which extends on adiameter of said semi-cylindrical tip member.

11. A hand tool according to claim 9, including spring means reactivebetween the handle member and the arms and being operative normally tobias the tip members to their spread relationship.

12. A hand tool according to claim 9, wherein one of said tip membershas its working edge termed as an inclined wedge adapted when said onetip member is being spread to knife into the gap of a ring with whichthe mandrel is engaged, and wherein spring means are provided which isnormally effective to bias the tip members to their spread relationshipand which is further efiiective following closing of the tip members andengagement of the mandrel with said ring to cause a firststage spreadingof the ring by forcing the working edge a limited distance into the ringgap.

13. A hand tool according to claim 9, wherein the relatively upper oneof said pair of parallel lever arms mounts a finger piece projectingtherefrom forwardly of the handle member for actuating said lever armsin unison in said one direction with respect to the handle member.

14. A hand tool for picking up split spring retaining rings individuallyfrom a supply thereof and assembling them on grooved shafts and likecylindrical workpieces comprising, in combination, a handle,complemental closable and spreadable tip members disposed forwardly andin generally right-angular disposition with respect to the handle andbeing together operative to form a ring gripping and spreading mandrelhaving effective diameter slightly less than that of the opening in saidrings when said tip members are in their relatively closed position andeffective diameter corresponding to that of the shaft on which ringassembly is to be effected when said tip members are in their relativelyspread-apart position, substantially parallel arm means extendingbetween said tip members and the handle and being pivotally connected tothe latter for limited swinging movement in unison with respect thereto,the length of said arm means and the locations of their points ofpivotal connection with the handle being such that when said arm meansare moved in uni-son with respect to the handle in one direction saidtip members are positively actuated from their spread-apart to theirclosed position, and when they are similarly moved but in the oppositedirection said tip members are positively actuated from their closed totheir spread-apart position, and a push head carried by said handlemember which is coaxial with the mandrel when the tip members thereofare in their spread-apart position and being operative to push a spreadring from the mandrel and over the end of said shaft.

15. A hand tool according to claim 14, wherein said arm means comprisesparallel arms pivotally connected to the handle means adjacent theirrelatively rearward ends for swinging movement in unison with respect tosaid handle member, the free ends of said arms extending forwardly fromthe forward end of said handle member, said tip member being mounted independing front and rear relationship on the free ends of said arm, theconstruction and arrangement being such that when said arms are swung inunison with respect to the handle member in one direction said tipmembers move in a mutually intersecting arcuate path as effects closingof the tip members and when said arms are similarly swung but in theopposite direction said tip members move in diverging arcuate paths aseffects opening of said tip members.

16. A hand tool according to claim 14, wherein the relatively upper oneof said parallel arm means mounts a finger piece projecting therefromforwardly of the handle for actuating said arm means in said onedirection and in unison with respect to the handle.

References Cited in the file of this patent UNITED STATES PATENTS SawdyJuly 24, 1951

1. A HAND TOOL FOR GRIPPING SPLIT SPRING RETAINING RINGS FROM WITHIN THEOPENING THEREOF AND THEREUPON ASSEMBLING SAID RINGS ON GROOVED SHAFTSAND LIKE CYLINDRICAL WORKPIECES COMPRISING, IN COMBINATION, AN ELONGATEDHANDLE MEMBER, COMPLEMENTAL AND DIAMETRICALLY TRANSLATABLE MEMBERSTOGETHER FORMING A RING GRIPPING AND SPREADING MANDREL, PARALLEL ARMMEANS PIVOTALLY CONNECTED TO SAID HANDLE MEMBER ADJACENT THEIR REARWARDENDS AND EXTENDING FORWARDLY FROM SAID HANDLE AND MOUNTING SAID TIPMEMBERS AT THEIR RELATIVELY FORWARD ENDS IN GENERALLY RIGHT-ANGULAR ANDMANDREL-FORMING RELATIONSHIP WITH RESPECT TO SAID HANDLE MEMBER, THEPIVOTAL CONNECTIONS OF SAID ARM MEANS TO HANDLE MEMBER PERMITTINGLIMITED RELATIVE ROTATIONAL MOVEMENT OF THE HANDLE MEMBER WITH RESPECTTO SAID ARM MEANS, THE LENGTH OF SAID ARM MEANS AND THE LOCATIONS OFTHEIR PIVOTAL CONNECTIONS TO THE HANDLE MEMBER BEING SUCH THATROTATIONAL MOVEMENT OF THE ARM MEANS IN UNISON WITH RESPECT TO THEHANDLE MEMBER IN ONE DIRECTION EFFECTS SWINGING MOVEMENT OF THE TIPMEMBERS IN MUTUALLY INTERSECTING ARCS AS EFFECTS TRANSLATORY MOVEMENT OFSAID MANDREL-FORMING TIP MEMBERS TOWARDS ONE ANOTHER BY AN AMOUNT SUCHTHAT THE MANDREL HAS EFFECTIVE DIAMETER SLIGHTLY LESS THAN THAT OF THEOPENING OF A RING TO BE ASSEMBLED AND THAT SUBSEQUENT ROTATIONALMOVEMENT OF THE HANDLE MEMBER IN THE OPPOSITE DIRECTION EFFECTS SWINGINGMOVEMENT OF THE TIP MEMBERS IN MUTUALLY DIVERGING PATHS AS EFFECTSTRANSLATORY MOVEMENT OF SAID MANDREL-FORMING TIP MEMBERS AWAY FROM ONEANOTHER BY AN AMOUNT SUCH THAT THE MANDREL HAS EFFECTIVE DIAMETERCORRESPONDING SUBSTANTIALLY TO THAT OF THE SHAFT ON WHICH SAID RING ISTO BE ASSEMBLED, AND MANDREL-TELESCOPING MEANS FIXEDLY MOUNTED ON AFORWARD EXTENSION OF SAID HANDLE MEMBER IN GENERAL AXIAL ALIGNMENT WITHSAID MANDREL AND BEING ADAPTED TO TELESCOPE OVER SAID MANDREL RESPONSIVETO ROTATIONAL MOVEMENT OF SAID HANDLE WITH RESPECT TO THE ARM MEANS ASAFORESAID, THEREBY TO PUSH A RING WHICH HAS BEEN GRIPPED AND SPREAD BYSAID MANDREL AXIALLY THEREFROM AND THENCE OVER AN END OF THE SHAFT TOTHE PLANE OF THE RING-SEATING GROOVE THEREOF.